ABSTRACT To evaluate the efficiency of an energy density of 0.05mj/mm2 of low intensity extracorporeal shockwave therapy (Li-ESWT) on erectile dysfunction (ED) patients.A total of 45 ED patients met the inclusion criteria, including 7 PDE5i responders and 38 nonresponders. All the patients have already been delivered 10000 shockwaves of total seven treatment points twice a week for 4 weeks. Simultaneously, questionnaires of International Index of Erectile Function-Erectile Function (IIEF-EF), Erectile Hard Score (EHS) and Minimal Clinical Important Differences (MCID) were evaluated for the efficiency and safety at 8th and 16th weeks.The changes in the IIEF-EF score by MCID suggested that Li-ESWT treatment was effective in 22 PDE5i nonresponders patients (58%) at 8th week. Then at 16th week the number of patients who were effectively treated increased to 27 (71%). Among PDE5i responders, 5 patients (71%) were effective base on MCID at 16th week. Among PDE5i nonresponders 22 patients (58%) achieved erection hard enough for vaginal penetration and increased to 27 (71%) patients at 16th week (EHS ≥3). Moreover, even 3 patients achieved EHS 4 in PDE5i nonresponders at 16th week. Among PDE5i responders, 4 of 7 patients reached EHS of 4 from EHS 3 at 16th week. Apart from this, Li-ESWT treatment was also effective in 9 patients (24%) in PDE5i nonresponders without follow-up PDE5i.Energy flux density (EFD) of 0.05 of Li-ESWT could improve the erectile function of ED patients with PDE5i response. In addition, EFD of 0.05 of Li-ESWT treatment could turn PDE5i nonresponders to responders.